Many of you may not know that the wideband sensor that DashPac sells in most of our products are genuine Bosch sensors. And I think many don't know these sensors will not last forever. These sensors are actually a bit delicate. The sensor will actually be very quickly damaged by water getting on or into the sensor. As many can imagine this is difficult at best when installing a sensor into a water jacketed exhaust manifold where the water is introduced into the exhaust not to far away from the location where most install the sensor.
Exhaust manifold sensor location is a very common place to locate the sensor. However we can give some tips to have a better success at drilling this hole without drilling into the water jacket and creating a water leak that will damage the sensor. When drilling the hole use a smaller drill bit just bigger than the tip on the sensor. use that bit to drill all the way down through the manifold into the exhaust system. now use a larger bit to drill just far enough in to get the tap just far enough in to make enough threads for the sensor. a very common mistake is to drill all the way with the bigger drill bit and run the tap all the way through the hole. Tapping the hole all the way through greatly increases your odds of nicking the water jacket with the tap and creating a leak.
Gutted water boxes are another problem for your sensor. Because water is always sitting in the water box gutting the water box can allow water to splash around (especially when trailering the ski) . If you have a gutted water box we highly recommend keeping a 7/8" wrench with you and removing the sensor after you are done with the ski for the day and before trailering the ski.
Also its good practice to remove the sensor at the end of the jet ski season after winterizing the ski, or just putting the ski away for a time.
What we recommend as the best solution and best sensor life is to mount the sensor in a spacer between the engine head and the exhaust manifold. This eliminates the chance of drilling into a water jacket, and also keeps the sensor away from the wet location of the exhaust system. The only down side to this is your only monitoring one of the three cylinders. this is typically not an issue but something to be aware of.
To recap there are many things you can do to help prolong the sensor life, but understand the watercraft exhaust design is hard on sensors.
Occasionally we will get a complaint that the sensor with DashPac dies, But if they use brand X controller the sensors are just fine. Most of the time this is still due to a water leak, bad head gasket, and or leaking intercooler. There are many different ways to drive the Bosch sensor. Most brand X controllers use a free air calibration setup. This means to keep the readings accurate you have to occasionally do this free air calibration. In this type of controller they are not using all the components of the sensor. With the DashPac controller we opted to go another route, we know most people will not pull the sensor and do a free air calibration regularly. So we opted to use the entire sensor and make our controller self calibrate each time the unit is turned on without the need to pull the sensor out and free air it. Now this makes the sensor a little more sensitive to water because we use the entire sensor. This is why its important to keep the sensor dry.
Even with the best location and practices it is not uncommon to have to replace the sensor occasionally. Due to all the above things being out of our control we cannot and will not warranty wideband sensors. Bosch will not warranty them so we can't either.